Question about DB of fans

BringTheRain · 13 Dec 2009 at 00:25

I have got some 17.5db fans in my pc at the moment and they are on a fan controller. I am looking at some other fans and they are 30db! i can still put them on a fan controller. But am i right in thinking they are gonna be twice as loud???? Or there abouts twice as loud???

Thanks

MagicBoy · 13 Dec 2009 at 00:36

Nope. db is a logarithmic scale. Assuming they were measured to the same spec 30db is many many times louder than 17db. Anything below 20db is pretty much inaudible in case fan terms.

BringTheRain · 13 Dec 2009 at 00:40

Oh plop. I have ordered the wrong ones from an auction site, as OCUK dont sell em

I have emailed the seller, as the fans i wanted were like an extra 60p each lol. Just hope he swaps em

Thanks tho

JonJ678 · 13 Dec 2009 at 00:40

MagicBoy said:
Assuming they were measured to the same spec

Which is a big assumption. For one thing the db reading depends on distance from source of noise, and few people bother to say at what distance it's measured. A safer approach is to just ignore the db reading completely and go on the opinion of spcr forums.

BringTheRain · 13 Dec 2009 at 12:11

Well I have got the green 4 led akasa fans 120mm and they are perfect for my needs. Rated at like 17db. I've ordered the wrong fans in red led and they are 30db. The other ones are 17db

. I'm hoping he willchange them for me. But he may not

WJA96 · 13 Dec 2009 at 12:22

The quoted dB figures for fans are mainly utter nonsense. They almost never quote the distance the noise was measured at and quite often they don't say if it's dB or dB(A) which can make quite a big difference. There is also the issue of 'intrusive' noise as some fans which look high dB(A) actually seem quiet because the noise they produce isn't 'intrusive'.

Check out Quiet PC Review for realistic fan test results. It makes for very interesting reading.

BringTheRain · 13 Dec 2009 at 12:51

Yeah but these are the same make and size. One is 17db and the other is 30db. So they are gonna be louder even if turn them right down. If he doesn't swap em out. I will re order and sell em

UnworthyBean · 13 Dec 2009 at 17:34

I have a couple of Akasa red fans and they are a bit loud on full speed. But If you have a fan controller then you have nothing to worry about. Nice and quiet (Or atleast to my ears anyway)

WJA96 · 13 Dec 2009 at 21:46

DAMO RAM80 said:
Yeah but these are the same make and size. One is 17db and the other is 30db. So they are gonna be louder even if turn them right down. If he doesn't swap em out. I will re order and sell em

The make is also highly confusing. Companies like Akasa don't make anything, they just buy stuff in and stick their brand on it. The fans they buy in September won't necessarily be thye same as the ones they source in October - it depends where they can get a deal.

If you read the SPCR stuff you'll see that consistency isn't a big thing in fans.

BringTheRain · 14 Dec 2009 at 09:43

Blimey thanks for the info and eye opening. I just want it to be quite lol. Ah well will wait and see what happens. Thanks everyone